The invention relates to a pressure control valve with a pressurized membrane for closing and opening a gas passage.
Holch, U.S. Pat. No. 5,090,393, for instance, discloses the integration of a pressure control valve in an intake path for the internal combustion engine of a motor vehicle. This pressure control valve is, for instance, installed in a ventilation line between the crankcase and the air intake duct or the air filter, or into the ventilation line of the fuel tank in a motor vehicle by means of two flanges. In each case, the object is to prevent the pressure or the negative pressure in the units that are to be vented from exceeding a predefined value. To this end, a membrane is provided, which by opening a duct, for instance against the force of a valve spring, controls the passage and closes it if necessary.
In this known arrangement, on the membrane side opposite the unit to be vented, a ventilation bore is present inside the valve housing, which pressurizes the valve chamber with atmospheric pressure. In many applications, however, the supply of atmospheric pressure is very complex, for example, if the pressure control valve is located in a sealed pressure chamber. In this case, the atmospheric or ambient pressure would have to be supplied by means of an additional duct or a hose or the like.
It is an object of the invention to provide an improved pressure control valve with a pressurized membrane for opening and closing a gas passage.
Another object of the invention is to provide a pressure control valve with a pressurized membrane for opening and closing a gas passage which is simply constructed in a space-saving manner.
It is also an object of the invention to provide a pressure control valve with a pressurized membrane for opening and closing a gas passage which can produced in a cost effective manner.
A still further object of the invention is to provide a pressure control valve with a pressurized membrane for opening and closing a gas passage which can be used to control venting of crankcase gases to an air intake of an internal combustion engine.
These and other objects of the invention are achieved by providing a pressure control valve with a pressurized membrane for closing and opening a gas passage, in which a valve chamber pressurized with an ambient pressure (Pamb) is provided on the side of the membrane opposite the gas passage to be closed and opened; the pressure control valve is arranged such that the gas passage has an exit which leads directly into a volume with ambient pressure (Pamb), and in the membrane there is a ventilation hole through which the valve chamber is directly pressurized with ambient pressure (Pamb).
Advantageously, the pressure control valve is arranged in such a way that the exit of the gas passage leads directly into a volume with ambient pressure, typically atmospheric pressure. The membrane comprises a ventilation hole, e.g., a bore, through which a valve chamber present on the side of the membrane opposite the gas passage to be closed and opened can be directly pressurized with ambient pressure.
The membrane in the valve chamber during closing is preferably pushed against the gas passage opening under pressure of a helical spring. The pressure control valve according to the invention can be easily used in an arrangement for venting a crankcase to the air intake tract of an internal combustion engine. It is advantageous that the pressure control valve can be integrated directly into a pressure body to save space without taking into account venting ducts, since it is unnecessary to construct any additional hoses or ducts in the device.
These and other features of preferred embodiments of the invention, in addition to being set forth in the claims, are also disclosed in the specification and/or the drawing, and the individual features each may be implemented in embodiments of the invention either individually or in the form of subcombinations of two or more features and can be applied to other fields of use and may constitute advantageous, separately protectable constructions for which protection is also claimed.